1. Field of the Invention
This invention relates to operating mechanisms for throwing multiple toggles in synchronism with one another.
2. Background of the Invention
It is frequently necessary in electrical installations that a number of toggle moulded case circuit breakers be toggled in synchronism with one another. One method of achieving this is by means of a tie bar acting on all the circuit breakers together. When such a tie bar is manually moved to toggle the circuit breakers it is, at least sometimes, the case that considerable force must be exerted on one section of the tie bar resulting in torque on the tie bar and inefficient use of force.
Any problems encountered in such mechanisms may be accentuated because the toggle circuit breakers involved are frequently heavy to operate and the combined force need for multiple circuit breakers may be quite great even when torque is not a relevant factor.
One or an arrangement of circuit breakers is frequently encountered within closed enclosures such as explosion proof enclosures, see, for example, U.S. Pat. No. 2,213,657 issued to Rowe on Oct. 12th, 1938 and describing the operation of one circuit breaker from outside an enclosure. The circuit breakers themselves may be arranged within the enclosure with the tie bar and are operated by leverage from a single manually operated handle projecting out of the enclosure. The arrangement and operation of electrical circuit breakers within explosion proof enclosures are governed by regulations in many countries. The regulations may differ from country to country but generally impose restrictions on the mechanism with a view towards safety.
In such systems, additional problems arise in that it is sometimes necessary to actually access the interior of the enclosure, after which a realignment of the operating mechanism of the circuit breakers may be difficult. When such an enclosure surrounds the circuit breakers, it is usually provided with a door and the operating mechanism for the circuit breakers may be located in the door. The door may be hinged onto the enclosure and, if it is opened for any reason, projecting parts of the operating mechanism for the circuit breakers may push the circuit breakers and toggle them during the closing arc of the door. Even if the circuit breakers are not toggled during closing movement of the door, it may be difficult to properly align the operating mechanism with the circuit breakers.
The problem of realignment after accessing the enclosure is so acute that in some instances arrangements have been made to access the circuit breakers through a back wall of the enclosure on which the circuit breakers themselves are located to avoid disturbance of the alignment of the operating system. Sometimes push button operating system which utilizes cams to move the circuit breakers maybe used but these systems also suffer from problems of realignment after opening the enclosure.